基于HHT信号分析的GFRP锚杆锚固质量无损检测方法研究

Research on non-destructive testing method of GFRP bolts based on HHT signal analysis

为优化土遗址GFRP锚固体系无损检测信号反演分析过程,采用希尔伯特-黄等信号处理方法,对多种完整锚固和缺陷锚固模型的检测信号进行分析。分析过程中首先通过巴特沃斯滤波法消除检测信号中的噪声,然后对消噪后的信号依次进行傅里叶和希尔伯特-黄变换(HHT)分析。试验发现,该处理方法能较为清晰地识别缺陷和杆底反射信号,从而更精确地反演出缺陷位置和锚固长度。此外,利用完整模型和缺陷模型杆底反射的时间差反演出的空浆缺陷长度也与预设工况相近。研究结果为土遗址GFRP锚固长度和空浆缺陷的位置与大小的反演提供了较为系统的分析方案。

Aiming to optimize the retrieval and analysis process of non-destructive testing(NDT)of GFRP anchorage system in earthen sites,the Hilbert-Huang transform(HHT)method was used in this study to analyze the test signals of various intact and defective anchoring models.In the process of analysis,the noise in the detected signal is firstly eliminated by Butterworth filter method,and then the signal after denoising is analyzed by Fourier and HHT methods successively.It is found that this method can clearly identify the defect and the reflection signal of the bottom of the rod,so as to reverse the defect position and the anchorage length more accurately.It is also shown that the pulp defect length,reversed according to the difference of the reflection times of complete and defect models,is accordance with the given conditions.The results provide a systematic analysis scheme for the inversion of the anchorage length of soil GFRP and the location and size of the pulp defect.